textproduct: Rapid City

KEY MESSAGES

- Warm through Memorial Day with daily isolated thunderstorms, mainly over the Black Hills

- Chances of showers and thunderstorms will increase Tuesday night and continue through the rest of the week

UPDATE

Issued at 950 PM MDT Sat May 23 2026

No big changes to the inherited forecast. Still expecting mostly dry conditions for the area through Monday. Main exceptions are some low end chances for rain showers tonight and low end chances for the Black Hills during the heat of the day.

For the rain showers tonight, hi-res models have been hinting at light rain showers tracking west-to-east through NE WY and the northern Black Hills. Latest satellite and radar imagery supports this idea as increased cloud cover and radar returns have been popping up in SW Montana. Without much support, these showers shouldn't amount to much in terms of impact to the area.

Otherwise, the rest of the forecast was allowed to ride.

DISCUSSION

(This Evening Through Saturday) Issued at 103 PM MDT Sat May 23 2026

Cyclonic flow continues across the northern Plains with several weak waves crossing western SD. Water vapor imagery shows some of these impulses crossing NW SD through the Black Hills. Satellite shows Cu field has developed over the Hills...and KUDX radar higher tilts show isolated convection trying to initiate across the eastern edge of the Hills. Water vapor also shows subsidence behind the waves crossing central WY which would limit NE WY development to extensive mid level clouds. Will make further pop adjustments over the next couple of hours. Quiet weather is expected tonight with lows generally in the 40s. Warm air advection will continue pushing in from the southwest late tonight through Sunday, with highs expected to reach the 80s across the plains and 70s over the Black Hills. Steep midlevel lapse rates are again expected Sunday afternoon with another weak wave crossing the area within zonal upper level flow. Could see more convection developing across the Black Hills, but would be isolated in nature. With high bases, precip that does develop may not reach the ground. Warmer temps are expected on Memorial Day as the upper ridge axis crosses the northern Plains. Highs are expected to reach the upper 80s to lower 90s. Could again see isolated storms over the Hills. Tuesday through the rest of next week could bring a big pattern shift. Models are showing a deep upper low over the western CONUS while strong ridging builds well into the northern/Canadian plains. Deep southerly to southeasterly flow will bring Gulf moisture into the central and northern Great Plains...and an increasing chances for showers and thunderstorms. How exactly this pans out remains to be seen, especially given the differences in how the ECM and GFS show precip developing each day through the week. But this will bring better chances for much-needed precipitation...and perhaps better chances for strong/severe weather.

AVIATION

(For the 12Z TAFS Through 12Z Monday Morning) Issued At 518 AM MDT Sun May 24 2026

VFR conditions are expected through the forecast period. Isolated thunderstorms may develop over/near the Black Hills this afternoon, but the TAF sites should not be impacted.

UNR WATCHES/WARNINGS/ADVISORIES

SD...None. WY...None.